Question: Solve for $a$ : $-26 + a = -20$
Answer: Add $26$ to both sides: $ \begin{eqnarray} \\ -26 + a &=& -20 \\ \\ {+26} && {+26} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-26 + a} &\hphantom{=}& \hphantom{-20} \\ a &=& -20 {+ 26} \\ \end{eqnarray} $ Simplify. $ a = 6$